Won't turn on. DFU mode when connected to pc.

My Iphone 7 turned itself off overnight.

When i try to turn it on, it won’t start.

Pressing Power button + Vol Down won’t do nothing.

When connected to computer, iTunes detect’s it and says it needs to do a repair but stops at half and gives error 4014.

3Utools detects the phone as being in DFU mode. When trying to flash it, the phone finally wakes, shows apple logo for about 8 seconds, (3Utools says it’s in recovery mode at this moment) but as soon as a spinning wheel appears under the apple, the screen turns black again (although you can see it stays with backlight), 3Utools says it’s disconnected for about 5 seconds and after that returns to DFU mode.

3Utools stops at 19%. (that’s when the apple logo disapears and the phone kind of reboots).